Strength and chloride resistance of the blended Portland cement mortar containing rice husk ash and ground river sand

In this paper, the strength and chloride penetration resistance of the blended Portland cement mortar containing rice husk ash (RHA) and ground river sand (GS) were studied. Portland cement type I (OPC) was partially replaced with RHA and GS and a blended of RHA and GS. The mortar mixtures were made with OPC containing 0-40 % of RHA and GS. RHA and GS with 3 % by weight retained on sieve No. 325 (opening 45 A mu m of sieve No. 325) were obtained using ball mill. The study includes compressive strength, rapid chloride penetration test, chloride ion diffusion coefficient and chloride penetration depth of mortars. Test results indicated that the use of RHA produced mortars with relatively high strength and excellent resistance to chloride penetration. However, the incorporation of GS reduced the strength and resistance to chloride penetration of mortars indicating that it asserted only the packing effect. The blend of equal portions of RHA and GS produced relatively high strength mortars with good resistance to chloride penetration which is probably due to the synergy of the pozzolanic effect of RHA and packing effect of GS.